Machine for molding plastic materials



July 15, 1947.

e. w. WACKER MACHINE FOR MOLDING PLASTIC MATERIALS Filed March 5, 194112 Sheets-Sheet l July 15, 1947. e. w. WACKER MACHINE FOR MOLDINGPLASTIC MATERIALS Filed March 5, 1941 12 Sheets-Sheet 2 July 15, 1947.w. wAcKER 2,423,914

MACHINE FOR MOLDING PLASTIC MATERIALS 7 Filed Marcfi 5, 1941 12 ShetS-Sheet 3 July 15, 1 947. G. w. wAcKER momma FOR MOLDING PLASTICMATERIALS Filed March 5, 1 941 12 Sheets-Sheet 4 July 15, 1947. .G. w.WACKER 2,423,914

MACHINE FOR MOLDING PLASTIC MATERIALS Filed March 5, 1941 12Sheets-Sheet 5 July l5, 1947. G, w, w c ER 2,423,914

MAbHINE FOR MOLDING PLASTIC MATERIALS I Fil'ed March 5, 1941 12sheets-sheet 6 July 15, 1947. e. w. wAcKER MACHINE FOR MOLDING PLASTICMATERIALS Filed March 5, 1941 12 Sheets-Sheet 8 l i Q? 7/ 7/12 7 NNN 0 &

febrgeWVVac/Cgr Q? July 15, 1947. W, wAc 2,423,914

MACHINE FOR MOLDING PLASTIC MATERIALS Filed March 5, 1941 12'Sheets-Sheet 9 9 v 'fza'anjor- George 29 July 15 1947. 5, w, w c2,423,914

' MACHINE .FOR MOLDING PLASTIC MATERIALS Filed Marh 5, 1941 12Sheets-Sheet 10 July 15, 1947. G. w. WACKER' 2,423,914

MACHINE FOR MOLDING PLASTIC MATERIALS Filed Maire h 5, 1941 12Sheets-Sheet 11 Jill/6155i GeayeWWczcker July 15, 1947.

F'i led March 5 1941 G. W. WACKER MACHINE FOR MOLDINGPLASIIC MATERIALS12 Sheets-Shet 12 Patented July 15, 1947 MACHINE FOR MOLDING PLASTICMATERIALS George W. Wacker, Cincinnati, Ohio, assignor to ClearingMachine Corporation, Chicago, 111., a corporation of IllinoisApplication March 5, 1941 Serial No. 381,841

13 Claims.

This invention relates to improvements in a machine and method ofmolding plastic materials, and one of the objects of the invention is toprovide an improved machine or press for processing material which hasbeen previously plasticized in a container or before being placed in acontainer, and is particularly adapted though not necessarily limited inits use for producing objects by injection process.

Heretofore it has been customary in injection molding machines of thischaracter which use thermoplastic or heat softening resins to supply thematerial in hard granular form and then introduce it into a heatingchamber within the machine to plasticize it to a point where it may beinjected or forced into a mold.

With such a press it necessitates considerable heat and time to reducethe material to such a state as to adapt it for such injection, with theresult that among other things, the capacity and speed with which themachine may be operated, is controlled by the length of time necessaryto properly heat the material and the use of such ,a method soon becomeseconomically impractical for the production of large pieces or objects.

Furthermore, in the prior machines it has been necessary to maintain thetemperature of the heating means considerably in excess of theplasticizing temperature in order to secure reasonable and rapid heattransfer from the heating means to the material. This results in muchdifficulty due to overheating and burning of the material.

Furthermore, with the prior machines, it has been-found necessary inorder to heat the material to break it up into small streams so that theheat may surround them while being passed through the heating chamber orzone. This results in objectionable resistance to the flow of thematerial through the restricted passages, requiring excessive pressures,aswell as presenting the objectionable and difiicult task of cleaningthe passages when changing the material or color. Furthermore,mechanical difficulties will be created by the high pressures necessaryand involved, causing leakage of the material past the plunger.

Furthermore, the prior machines are limited in use to thermoplastic orheat softening materials, and it is one of the objects of the presentinvention to provide an apparatus which is adapted to handle a widevariety of molding materials includingthermosetting resins, rubber andthe I like.

The articles molded or'formed by the prior machines are more or lesslimited in mass or section, as a result of shrinkage due to dissipationof the heat in cooling, and in the inability of such machines toovercome such difliculty, for the reason that the material is forcedinto the mold through sprues or runners, and the portion of the materialin the sprues may chill before the material in the mold cavities proper.The chilling or cooling of this portion of the material causes it tobecome set or hard and it cannot then be forced into comminglingrelation with the material which is in the mold cavity, in an attempt tocompensate such shrinkage.

To provide a machine for molding plastic materials which will overcomethese and other difliculties and objections is another object of thepresent invention.

A further object is to provide in a machine or press of thi characterfor injection molding, improved means whereby the heating of theplasticized material within the machine is dispensed with, and in theoperation of which machine the material will be heated and plasticizedby means entirely separate from or outside the machine or press.

A further object is to provide improved means to prevent chilling of thepreheated material after it has been placed in the machine and prior toinjection into the mold cavity, by maintaining the temperature of theinjection chamber, i. e. the,

chamber which receives the packaged material prior to its injection intothe mold cavity, only at a temperature to maintain the material in itspreheated plasticized condition.

A further object is to provide an improved machine which may be operatedwith an injection chamber at substantially room temperature, and whichwill require neither heating nor cooling means.

A further object is to provide improved means for exerting pressure uponthe mold elements to close the same, and improved means for increasingsuch pressure whereby to overcome the internal pressure of the moldcreated by forcing the material into the mold cavity.

A further object is to provide improved means for delivering a supply ofmaterial into the mold cavity, and improved means for augmenting thesupply of material in such cavity to compensate shrinkage of thematerial and thereby insure accuracy in the product or article itself.

A further object is to provide in a machine of this character animproved platen for carrying and manipulating the mold and improvedmeans for controlling the operation of the platen.

which chamber is closed by one of the mold e1e-.

ments, and improved means whereby the mold may be raised to cover oropen the injection chamber to permit free and unrestricted access to theinterior of the chamberand-ofthe placing of the material into suchchamber.

A further object is to provide improved knock out mechanism for thearticle 'and improved means for rendering the knockout mechanism activeand inactive at will.

A further object is to provide in a machine of this character a platencooperating with the mold and operating with acomparativelylong strokeand comparativelylow pressure; a ram operating with acomparativelyishort stroke with great pressure, and an element adapted vto beinterposed between the ram .and platen whereby the .pressureoftthe ramwill be exerted upon the platenin addition to the pressure directlyacting .upontheplaten, the said element being withdrawn from between theplaten and ram to pervmitthe raising of the platen andthe mold.

Aiurther obj ect isto provide means to control the movement of theplatentoimpart two distinct closing positions of the mold, and toprevent the clamping thrust'of the platen from being exerted upon themold.

A further object is to provide in a machine of this character improvedmeans whereby twosteps of .pressure may-be exerted upon the ram.

.The preferred form of mechanism has been illustrated inthe accompanyingdrawings and described in connection therewith, but it is to beunderstood thatvarious changes may be made in .plungerbeing shown at theend of one injection stroke, with the .chamber in its upper position.

Figure 4 is a detail sectional View on an enlarged scale, taken on line44 Figure 1 and showing the portion of the mechanism which is .disposed,belowthe bed. of the machine, the injection plunger being shownretracted after completing the injection of material into the mold, andthe chamber being in its lower position.

Figure 5 is a view similar to Figure 3 with parts omitted and on anenlarged scale, showing some of the .partsin a different position.

Figure 6 is a view similar to Fig. .3 with parts omitted, and with thefiller member that is to be inserted betweenthe ram and platen in aninoperative position and with the ejecting mechanism in operativeposition. I

1 Figure 7 is a detail view partly -in plan and partly broken away andas taken on lined-l Figure 6.

Figure 8 is a diagrammatic view of the fluid or hydraulic system.

Figure 9 is an enlarged detail sectional view of 'one form of moldembodying a supplementary chamber for the material and the means forejecting the supplementary supply into the mold chamber, thesupplemental supply having been forced into the mold cavity, and thework being ready to be removed.

Figure 10 is a front elevation of one form of -mechanism-for locking themold sections together, for providing the initial separation of the moldsections.

Figure -11 is a; sectional view taken on line Figure 12 is a sectionalview of one form of mold and the means for arresting the movement of onesection towards the other.

Figure 13 is a view similar to Figure 12 showing the parts in differentpositions.

Fig. 14 is-a view, partly in elevation and partly in section, of oneform of container, showing the container with its charge of material andready to be insertedinto the injection chamber.

Fig. .15 is a View similar to Fig. 14, showing the action of thecontainer after the injection plunger has advanced sufficiently in itsstroke to place the contents of the container under pressure sufficientto expand the container against the chamberwall, but not sufficienttoiron out the convolutions of the container body.

Fig. 16 shows the container after one shot of material has beenforcedinto the mold under high pressure, with the convolutions ironedout and both material and container wedged into the chamber, and theplunger retracted, the-separation of the remainder of the material froma cool mold beingshown.

Figures 17, 18 and 19 are detail views partly in section and partlybroken away of another form of container for the material.

Figures 20, 21, '22, 23, 24, 25 and 26 are detail views partly inelevation and partly in section of valve mechanisms employed in thissystem and method.

Thepress consists essentially of a bed 20 which may be mountedupon asuitable base 2|, uprights 22 and a crown 23, constructed in any desiredor suitable manner either'integrally or of a sectional construction andif ofa sectional construction the parts'may be fastened or securedtogether in any desired manner or by means of tie rods.

Reciprocable between the uprights is a platen .24 and the ends ofthe'platen preferably project between and beyond cooperating uprights22, as shown more clearly in'Figure 1. The platen may be guided in itsreciprocating movement in any suitable mannersuch as by means ofdepending guide members 25 that are secured to the platen prefer-ablybeyond the uprights 22 and pass through-guides z t-secured to the bed20.

If desired, additional guides 21 may be provided which extend above theplaten beyond the uprights-'22 and-project-thereabove so as to movethrough suitable guideways, which latter may be a portion of brackets 28secured to the crown 23.

The platen is raised or..loweredor given a reciprocating movementthrough the medium of fluid-operating'mechanismsuch as cylinders 29 thataresupported by the crown 23 and in which cylinders (see also FigureS)pistons 30 reciprocate, the pistons being connected respectively bymeans of rods 31 with the platen 24 in any suitable manner.

' Fluid pressure is admitted into the cylinders 29, in a manner to behereinafter described, by means of pipes 32 which enter the bottom ofthe cylinders beneath the piston 30 so as to raise the platen and bymeans of pipes 33 above the pistons to lower the platen, the fluidpressure being supplied from a suitable source and being controlled inits direction of flow by suitable valves, all of which later will bedescribed.

Arranged above the bed 20 is a ram 34 (see particularly Figures 3 and 5)which operates in a cylinder 35 in the crown 23. The cylinder 35 is openat its bottom and is closed by means of a gland or annular member 35.which projects into a'recess 37 preferably formed as an enlargement ofthe cylinder 35, and is held in position in any suitable manner such asby means of screws or bolts 38.

The :portion 39 of the ram 34 within the cylinder 35 is of a diameterslightly larger than the diameter of the portion which passes throughthe gland or annular member 36 so as to form a circumferential shoulder4a which is adapted, whenthe piston reaches a predetermined point in itslowering movement to contact with the end 4| of the gland or annularmember 36 and thereby serves as a stop for limiting the movement of theram in a downward direction.

Suitable packing E2 and a packing gland 43 may be provided to form afluid tight joint for the ram and the packing gland 43 is held inposition by means of the usual bolts 44.

If desired. the periphery of the gland 36 may be provided with ashoulder 45 to form an abutment for the gland.

The ram is raised in the cylinder 35 by fluid pressure admitted from asuitable source through a pipe 35 and through the inlet 41, and thefluid pressure is admitted to the other side of the ram through apassage 48, a control valve 49 being provided to control the directionof flow of the fluid.

The ram 34 is adapted for a comparatively short extent of movement whilethe platen 24 is adapted for a comparatively long extent of movement,and the extent of lowering movement of the ram with respect to theextent of the lowerin movement of the platen is such that when theplaten is at the end of its stroke, and the ram at the limit of itsthrow, the ram will be spaced a considerable distance above the platen.

Therefore in order that the pressure of the ram will operate upon theplaten when the latter is in its lowermost position, a filler member 50is provided which is adapted to be moved into and out of the spacebetween the ram and the platen.

This filler member may be of any desired or suitable construction and isadapted to be moved in guideways 5| formed in a member 52 which latteris secured in any desired or suitable manner such as by means of bolts53 (see Figs. 1 and 3') to the end of the ram 34. The member 52 is of aconsiderable length, and the filler member may be provided with ears orprojections 54 that move in the guideways.

This filler member 50 is of such a size that when the platen is in itslowermost position, and the ram is in its elevated position, the fillermember may be moved into the space between the platen and ram, so thatwhen the ram is then lowered the force of the ram will be exerted uponthe platen through the medium of the filler member to hold the platenagainst raising movement,

which raising movement would result from pressure beneath the platen.

The pressures exerted in the cylinders 23 is not sulficient to hold theplaten against rising movement under pressure under predeterminedconditions and therefore the pressure of the ram 34 augments thepressure exerted by the cylinders 29 upon the platen to hold the platenagainst rising movement.

The member 52 may, if desired, be provided with a projecting portion 54(see particularly Fig. 3) which enters a recess 55 in the end of themember 34 and this assists in holding the member 52 in position and willrelieve the bolts of lateral stress.

The filler member 50 may be moved into and out of position with respectto the ram 34 in any desired or suitable manner. A simple and efficientmeans for accomplishing this result embodies a cylinder and pistonelement, and in order to provide a means whereby the extent of movementof the flller member may be accomplished, without unduly extending thelength of the cylinder, there may be provided a tubular member 55 (seeparticularly Figure 6) within which there is provided another tubularmember 5? of a considerably smaller external diameter to provide anannular space 58 between the two tubular members. The spacing of thesetubular members may be accomplished in any suitable manner. Within theinner tubular member is arranged a piston 59 to which is connected apiston rod 613 to the forward end of which rod is connected, as at 5!, acap 52, suitable packing 63 being provided to form a fluid tight jointbetween the piston rod and the end 64 of the inner tubular member 51.This end member 64 may be removably secured to the end of the tubularmemher 5'! by means of suitable bolts 55 and the inner tubular membermay be provided with a shoulder 56 which abuts the end 61 of the outertubular member 55. An opening 68 is provided in the end of the innertubular member 51 to which opening a pipe 63 is connected through whichfluid pressure from a suitable source of supply is admitted into thecylinder formed by the tubular member 57 on one side of the pistonOpenings Iii are provided in the wall of the inner tubular member orcylinder 57 adjacent the opposite end thereof to form communicationbetween the tubular member 5? and the tubular member 55 so that fluidentering into the space 58 between these tubular members 55 and 5'! willflow through the openings it) to the opposite side of the piston 59 tomove it in the opposite direction.

A pipe H has communication with the space 58 between the tubular membersso that when fluid pressure is admitted into the pipe H (seeparticularly Figure 6) it will flow through the space 58 in thedirection of the arrows, thence through the opening to into the tubularmember 51 to operate on the piston 59 and move it in the oppositedirection. Fluid which is in the tubular member 51 will then be forcedout through the pipe 63. When the direction of flow of fluid isreversed, that is, when the fluid is admitted through the pipe 69 tomove the piston in a forward direction, the direction of flow abovedescribed will be reversed and the fluid will pass out of the cylinderor tubular member 5"! through the opening Hi thence through the space 58and outthrough the pipe H. The direction of flow of the fluid iscontrolled by means of a control valve 72 (see Figure 8) the specificconstruction of which will be later described.

ported by the member 52 that is secured to the ram 35 in any desired orsuitablemanner such as a bar or member 75 which is connected to the endof the cylinder, and project beyond cpposite sides thereof. Supportingor anchoring bars or rods '89 are secured to the member 52 and also at"a"? to the member I 50 that the cylinders tad-4i? will be raised andlowered with the ram; The filler member is provided with an opening i9therethrough into which the forward end of the cylinder Eiiprojects.manifest that by manipulation of the piston 59 the filler member 55 maybe moved forwardly or backwardly, sliding in the guideways 55 so as toposition it between the ram and the platen or to move it out of suchposition, and the operation or manipulation of this filler member 59 iscontrolled by the operation of the valve 12.

In order to increase the pressure of the upon the platen when the fillermember 5B is in position between the platen and the ram so as toovercome or resist the tendency of excessive pressure beneath the platento raise the latter, and to a degree greater than the pressure possibleto obtain by only the line pressure or the operating pressure within thecylinder 9'3, means are provided whereby the pressure in the cylinder 3%may be increased. To that end there may be provided a plunger 59 (seeparticularly Figures 3 and 5),'which is arranged preferabl adjacent theupper-end of the cylinder 3'5 to operate in a plane transverse to theplane of the vertical movement of the ram 34. This plungeris preferablyconnected to a piston 89 which operates in a cylinder 3! suitablysupported, and fluid pressure is supplied through a pipe to the cylinderso as to move the plunger 9 forwardly and project the same into thecylinder 35 beyond the end of the ram, thereby reducing the volumetriccapacity of the cylinder with the result that an additional pressurewill be imparted to the fluid therein. Suitable packing 83 may beprovided for the plunger r 'In order to prevent interference of the ramB l with the operation of the plunger '59, there may be provided aprojection 84 on the end of the rain which, when the ram is at the limitof its uppermost movement engages a projection or shoulder 85 on theinterior surface of the wall, thereby providing a space into which theplunger '59 may be forced. The flow of fluidpressure into and out of thecylinder is controlledby means of a control valve somewhat similar tothe valves '52 and 59 and is adapted to be operated to direct the fluidpressure into one end of the cylinder iii and to permit the fluid toflow out of the same end thereof at zero pressure.

Below the bed 29 of the press is arranged a cylinder 3? in whichoperates a piston 88. The cylinder an is supported beneath the'bed 2B ofthe press in any suitable manner, such as by means of a cylinder head 99being secured by means of fastening bolts to the Connected to the piston98 is 'a piston rod 9i that eX- tends through a stuffing box'92 and tothee nd of the piston rod is connected an injection plunger It willtherefore be "93by means of a suitable coupling 94, the rod and plungerbeing preferably arranged in alinement.

The bed 29 of the press has provided therein an opening 95- whichpreferably increases in diameter from the top to the bottom of the bedso as to form a conical space '96 which communicates or forms the end ofa chamber 91. Adjacent the bottom of the chamber 9'! is an inwardlyprojecting annular flange 98 upon which a resilient annular packingmember 99 rests, the opening-in the packing registering with the openingin the flange.

Abearing member 99 is provided with a circumferential peripheral flangeII]! which latter, when the end of the bearing I99'projects through theregistering openings in the element 99 and flange 98, will rest upon theresilient element 99. The external diameter of the bearing I09 above theflange I91 is considerably less than the internaldiameter of the chamber9"! and this member 'isof a length to terminate considerably short of.the upper end of the chamber.

1 Because the injection chamber temperature has anegligible effect uponthe relatively large masses of molding material used in this machine,the chamber, in many instances, may be operated at room temperature, andno heating or cooling means need be provided, especially when thecharges of material are used. for single shot molding. Such heattransfer from the charge to the chamber as will. occur during the briefperiod required for the injection stroke will at best only affect a skinof material adjacent the chamber wall, and this skin will instantly pickup heat when being forced through the restricted sprue orifice with therest of the mass.

Resting. upon the top of the bearing I09 and preferably in a recess I92is a tubular member I93, the latter being provided with a flange I04 atthe base thereof to enter the said recess I02. This tubular member 503constitutes what will hereinafter be designated as an injection chamberand encompassing the injection chamber is a; collar Io5which serves as ameans to reinforce the-member I99 against bursting, and encompassing themember I95 is another member I06 whichlattermay beprovided with'suitableopen- .in'gs through which a heating or cooling medium maybe circulatedif desired; or, if desired, heating means may be provided in lieu of theopenings. This heating means is provided so as to maintain the injectionchamber only at a sufficient temper: ature to :prevent chilling of thematerial to be operated upon and which is contained within the chamberand to prevent a dissipation of the heat fromlthe material throughoutthe machine.

Connected to the piston 9i preferably below the .coupling 9c is a discor member I91 and passing through this member I97 are any desired numberof rods or pins I98 which have attached thereto and beneath the memberI91 a nut or collar I99, the rods I98 being adapted to slide freelythrough the member I91. These rods pass loosely through the flange 98and also through the resilient packing 99 being anchored at their freeends, a at H39 to the bearing I99 by being threaded into the flange IBI.

The upper end of the injection chamber I03 is 'disposed in alinementwith the opening and the open end of the injection chamber is less thanthe diameter of the opening 95 and the normal tendency of the resilientelement 99 is to move the end of the injection chamber toward theopening 95, when the piston 88 is raised.

When, however, the piston 88 is lowered the resilient member 99 will beplaced under compression through the medium of the rods I08 and thiswill draw the end of the injection chamber away from the bottom of theopening 96 to provide a space I I between the end of the injectionchamber and the bottom of the opening 96. This also provides anexpansion space for the material within the injection chamber and beyondthe end of the material remaining in the injection chamber and thebottom of the mold III, when making more than one shot from the supplyof material in the injection chamber. This is accomplished' in thefollowing manner:

Resting upon the bed 20 of the press is a section III of a mold whichlatter is provided with a sprue or runner II2. Extending from the bottommold section I II is a projection H3 which is of a diameter to fitwithin and fill the opening 95. A portion of the projection II 3 isreduced as at H4 and the external diameter of the reduced portion II 4is a close sliding fit into the open end of the injection chamber I03 toform a closure therefor.

As the piston 88 rises by reason of fluid pressure being forced into thebottom of the cylinder 81 below the piston through the pipe H5, themember I01 carried by the piston will rise and the plunger will alsorise within the injection chamber tending to force the materialtherefrom into the sprue. As the member I0I rises, the tendency of theresilient element 99 is to expand and by expanding will raise thebearing I00 together with the injection chamber I03 to move the end ofthe latter into engagement with the bottom of the mold section III. Anyfluid in the cylinder 81 on the other side of the piston 88 will beforced out of the pipe H6. The direction of flow of the fluid into andout of the cylinder 81 will be controlled by a valve II'I similar inconstruction to the valves 49, I2 and 80.

After the molding operation, the direction of flow of fluid is reversedby the valve II'I causing the pressure beneath the piston 88 to berelieved and also causing pressure to be exerted upon the top side ofthe piston 88. As the piston descends it will draw with it the plunger93 until the member I0'I contacts the ends or collar I09 on the rod I 08whereupon further descent of the piston 88 will move the member I0Idownwardly causing it to engage the ends or collar I09 to draw thebearing member I 00 downwardly against the stress of the resilientelement 99, with the result that the space IIO between the end of theinjection chamber I 03 and the bottom of the mold section III will bere-established.

It will thus be seen that the reciprocable chamber [I3 is provided withtwo definite operative positions with respect to the lower mold sectionIII. On the injection stroke of the plunger 93 the chamber will occupy aposition near the mold section I I I, while on the retraction stroke ofthe plunger the chamber will be caused to occupy the position removedfrom the mold section. But in both these positions, the operativeassociation of the chamber and the mold is such as to provide aleak-proof connection between said mold and chamber.

One object of this telescopic relation is to provide an expansion spacefor the material remaining in the injection chamber after an injectionshot. Such material is under considerable residual pressure, and unlessmeans are provided to dissipate this pressure, molding material willcontinue to ooze or bleed into the mold section I I I during the removalof the work from the section I2I. This expansion space is shown in Figs.16 and 19.

Another reason for this telescopic relation is that sometimes the moldsare quite cool, and it is important that the material remaining afterany shot be separated from the cool under surface of the projection II4, so as to prevent the premature chilling and hardening of the uppersurface of the material. Such chilling as takes place during the briefcontact on the injection stroke is compensated for by heat transfer fromthe main body of the remaining material.

The chamber 9'! may be employed as a container for a cooling liquid,such as water or the like, which may be supplied through a suitable pipeII8 from any suitable source and which pipe has connection with thechamber through a passage H9 that in turn communicates with the chamber9?, an overflow passage lI9-a being provided to maintain the desiredwater level in the chamber 9'5. Air circulation passages I20 may also beprovided in the bed of the press for maintaining the parts cool.

Cooperating with the mold section III is another mold section I 2I andthese mold sections may be of any desired or suitable construction andpreferably embody knockout pins I22 with which a knockout plate I23cooperates, as is usual in molds of this character. The extension II3 ofthe mold section III fits into the opening 95 in the bed and serves as ameans for maintaining the section against displacement with respect tothe surface of the bed upon which it rests and the mold sections may besecured together in any desired or well known manner.

The section I2I of the mold is secured in any suitable manner to theplaten 24 so as to be raised and lowered by the latter, and therebyseparate the mold sections so as to permit the ejection or knockoutof.the article I24.

The material to be molded is plasticized before it is placed withinthe'injection chamber I03,

and in order to accomplish this, it is necessary to raise the moldsection II I. This is accomplished because the mold section III is atthat time attached to the mold section I2I, which latter is attached tothe platen 24. In the operation of the machine, an article is molded andthe two sections I 2I and III of the mold are raised by the platen so asto permit of the insertion of more material into the injection chamberwhen the material that remains in the chamber is sufiicient for anothershot. The raising of the mold section III will uncover the opening 95 sothat the material may be placed into the injection chamber through thisopening. While the new charge of material is being inserted and whilethe mold is being raised by the platen, the material in the mold will begiven an opportunity to set after which the platen is lowered and thenthe upper section of the mold I2I only is raised so as to permit of theoperation of the knockout pins I22 to knockout the article from themold. This is accomplished by means of knockout pin operating mechanism(see particularly Figures 3, 5 and 6). Within the platen 24 is arrangeda series of pins I25, any number of which may be provided and which areadapted to be projected below the bottom of the platen. These pins areprovided with heads I25 operating in recesses I27 and beneath the headsI26 and within the recesses are springs I28 which tend normally to raisethe pins I25 and hold them in inoperative position so that during theordinary operation of the press and when the filler 11 member 59' is inengagement with the platen to exert pressure on the latter, these pinswill be forced upwardly by means of the springs I28 as shown moreclearly in Figure 3.

When it is desired to eject or knock out the article I24 from the mold,the ram 34 is raised and-the filler member 59 is moved from between theram and the platen and into an inoperative position by withdrawing thesame causing it to slide along the guideways in the member 52. Theknockout pin operating mechanism is then placed into position betweenthe ram and the platen. This mechanism embodies a member I29 which ismounted to slide in the guideways 5| in the member 52 and is normallydisconnected from the filler member 59.

This member I29 is provided with depending pins or projections I39 onefor each of the pins I in the platen 24 and is held in an inoperativeposition and to one side of the machine in any desired or suitablemanner, such as by means of a latch or catch I3I which is connected to ashaft I32, the latter being mounted or supported by the member 52.Connected to the shaft I32 is a lever I33 to the ends I34 of which maybe attached operating cords or elements I35 so that by rocking the leverI33 the catch I3I will be moved into and out of operative position so asto enter or to be moved out of the opening I35 in'a plate or extensiOnI3I that is secured to the member I29 (see also Figure 6).

To move the operating mechanism I29 into position with respect to theplaten, there is provided a coupling betweenthe element 62 which isoperated by the piston 59 and the member I29 which may be of any desiredor suitable construction.

A suitable construction, however, embodies a headed pin or extension I38(see Figures 5 and 6) that is adapted to enter a socket I39 carried bythe member I29; construction but may embody spring controlled pins orballs adapted to be projected under the head of the pin I38 when thelatter is seated in the socket I39; The stress of the springs issufiicient to cause the member I29 to be locked to theelement 62, so asto be drawn into'position between the plunger and the platen when thecatch I3I is inoperative.

When, however, the member I29 is moved out Ofoperating position betweenthe ram an the platen and when the catch I3I again enters the opening,I36 in the plate I31 to hold the member I29against movement with theelement 62, the coupling I38--I39 will yield and the member I29 will beheld in an inoperative position while the element 62 and the. fillermember 59 are retracted.

When the parts are in, the position shown in Figure 6, that .is, whenthe member I29 and the operating pins I39 are in alinement with theejector or knockout pin'mechanism. I 25, and when the platen is raisedto raise the upper section I2 I of the mold, the pins I39 will. operateuponthe pins I25 to cause them to project beneath the platen and forcedownwardly the plate I23 to which the pins I22 are attached therebyknocking out the. articleas shown more clearly in Figure 60f thedrawing,

As means for holding the catch I 3| in either of its positions there maybe provided a spring controlled pin I49 which is adapted to enter one ofthe recesses MI in an arm or extension I42 carried by the lever I33 asshown more clearly in Figures 2 and 5. If desired, any suitablemeans maybe provided for heating or coolingthe mold This socket may be of anyportedcby the platen24 or the guides 21 are pipes 5. I45 which havecommunication with the passages 1 These pipes I45 may be in themoldsections. supported by a suitable bracket I 45 (see particularlyFigureZ) and telescope respectively into tubular members I41, the upperend I48of which is closed. A pipe I49 is connected to one of'thesetubular members I 41 and a similar pipe I59 is. connected to the otherof the members I4! 50- that a heating or coolin'ggfluid may becirculated through the mold byfiowing; into the pipe I49,

, thence through one of the tubular members I41,

one of the pipes I45, through the passages I43 and thence out throughthe other pipe I45I4I and out through the pipe I59:

By this arrangement it will be manifest that rigid pipes may beemployedin lieu of flexible hose as the reciprocation of the platen will notinterfere with these pipes, the pipes I45'being movable into and out ofthe pipes I4! respectively as the platen 24 is raised or lowered.

The main pressure'fiuid for the system is supplied from any suitablesource through a pipe I5 I,

reference being had particularly to the diagram in Figure 8, which pipeis connected with a pump I 52 that in turn is operated by a motor I53.Leading from the pump I52 is a pipe I54 which has connection with a pipeI55'the latter in turn-being connected by means of a branch through; themedium of pipe I55 with the l-way valve II! which latter controls thedirection of flow ofthe fluid with respect to the piston 88;"

This pipe I55 is connected by means of a pipe I58 with oneside of amanually controlled valve I59 and connected also to the valve I59 is anexhaust or outlet pipe I59. A pipe I 5| leads 5 from the casing of thevalve E59 and communicates with the pipe 33 which in turn hascommunication with the platen raisin and lowering cylinders 29'on oneside of the piston 30; The valve I59 also has communication by means ofa pipe I62 which in turn has communication with the pipe 32 leading-tothe cylinders 29 on the other side of the piston 39 and in the pipe I58may be provided a globe valve I53. The valve I59 is manually operated inany suitable manner such as by means of an operating lever or handleI94. This valve will be specifically described later.

Both of the pipes I6'II52 serve as fluid inlet and fluid outlet pipesfor the cylinders 29.- That is, when the valve I59 is set so as todirect the fluid into the cylinder 29 on the top side of the piston thfluid on the other side of the piston will flow out through the pipe 32,pipe I62, through the valve I59 and into the exhaust pipe I60. When thevalve I59 is reversed, the direction of flow of the fluid will also bereversed.

As a means for preventing a sudden blow against the mold faces when theplaten is lowcred, cushion means is provided in the cylinders 29 andcomprises a pip I of a very small diameter which leads from the end ofthe cylinders below the piston 30 and has communication with the pipeI62 by means of a valve I55. This valve I96 may be of any desired orsuitable construction such as an ordinary o'penand shut valve that isadapted to be opened toany degree or extent so as to control the size ofthe passage through which the fluid, being forced out of the cylinders29, will flow back into the pipe I52. It will therefore be manifest thatinasmuch as the pipe I95 is of a smaller diameter and when the fluid istrapped'between the piston and the end of the cylinder, it will flowsolely through the pipe I55 and thereby form a cushion.

The pipe 32 has communication with the cylinder 29 at a higher elevationthan the point at which the pipe I65 has communication with the cylinderand it will be seen that during the first part of the descent of thepiston 30 in the cylinder 29, fluid will be forced out through the pipe32 but, when the piston 30 assumes a position to close the pipe 32 andthe corresponding opening in the cylinder 29, the only escape for thefluid will be through the pipe I55 and as this pipe is of acomparatively small diameter with respect to the pipe 32 the escape ofthe fluid will be greatly retarded.

The pipe I55 also has communication with another pipe IBI that leads tothe valve 49 the specific construction of which will be laterdescribed,'but is preferably of the 4-way type and is the valve whichcontrols the flow of fluid through the pipes 4548 of the ram 34. Thecasing of the valve 49 i also connected to an exhaust pipe I68. 1

Similarly the pipe I55 is connected by means of a branch I69 with thevalve 85 which controls the admission of the fluid operating pressure tothe cylinder 8I that actuates the plunger 59 which operates to intensifythe pressure of the fluid in the cylinder 35, as will be laterdescribed, and within this pipe I 59 may b arranged a check valve III.Leading from the casing of the valve 86 is an exhaust pipe IIIl.

Leading from the pipe I55 is another pipe II2 which has communicationwith th valve mechanism I2, the latter operating to control thedirection of flow of the fluid through the pipes 69 II for moving thefiller member 50 into and out of position between the ram and theplaten, and leading from the casing of the valve I2 is a dischargeoutlet pipe "4.

Thus it will be seen that the pump I52 receiving its supply of fluidthrough th pipe I! will direct the same through the pipe I54 and intothe pipe I55 to be distributed to th various mechanisms, a check valve Ibeing provided between the pipes I54 and I55.

The pump I52 is a continuously operating pump and will establish andmaintain a pressure in the line through the pipe I55 andby controllingthe respective valves 49-12-436 and I I1 the direction of flow of thefluid will be controlled to move the respective parts accordingly, theraising and lowering movement of the platen being controlled by thevalve I59.

The valves 49-I2-86 and III are fluid actuated valves and pressure issupplied to actuate these valves by means of a pump I'I5 which receivesits supply through a pipe III leading from the source of supply. Thepump discharges into a pipe I18 and this pipe with the branches whichare attached thereto are of a smaller diameter than the diameter of thepipe I55 with the various pipes attached to the latter and in thedescription of the pipe H8 and its communicating pipes which convey thefluid pressure to the valve to operate them will hereinafter bedesignated as the pilot pipes or pilot system. This pilot pipe II8 hascommunication with a pipe Il9 with a manually operated valve I80 andleading from the casing of the valve I89 is a pipe I8I which connectswith an exhaust pipe I82. Leading also from the valve casing I80 is apilot pip I83 which has communication with the casing of the valve 49and a second pilot pipe I34 also has communication with the casing ofthe valve 49, and the valve I80, so that by manipulating the valve I thedirection of flow of the fluid through the pilot line to the valve 49will be controlled and thereby the raising and lowering movement of thepiston 39 in the cylinder 35 which controls the movement of the ram willbe controlled.

Similarly leading from th pipe II8 is another pipe I which connects tothe casing of a valve I85 and leading from the valve I86 is another pipeI8! which communicates with the exhaust pipe I82. The valve I85 ismanually controllable and leading from the valve I85 is a pipe I88 whichhas communication with the valve 85 and another pipe I89 also hascommunication with the valve I 86 and the valve 86 so that bypositioning the valve I86 in one position, fluid pressure from the pipeI69 will enter the cylinder 8| to advance the piston 99 and the plungerI9 to force the latter into the cylinder 35 and thereby intensify orincrease the fluid pressure in the cylinder 35 against the piston 39.

When the valve I85 is set to exhaust the fluid pressure from thecylinder 8 I, the pressur in the cylinder 35 will operate upon the endof the plunger I9 to force the piston 80 backwardly in the cylinder SIso that the fluid in the cylinder 8| behind the piston will flow throughthe valve 83, thence through the pipe I'm back to the exhaust or tank.Still another pipe I90 forms communication between the pipe I78 and avalve casing IN, the latter having a valve therein which is preferablymanually operated and a pipe I92 forms communication between the valvecasing I9I and the exhaust pipe I 82.

Leading also from the valve casing I9I is a pipe I93 which hascommunication with the casing of the valve I2 and another pipe I94 formscommunication between the casing of the valve I2 and the casing of thevalve I9I with the result that when the valve I9! is set so as to directthe fluid pressure from the pilot system through the pipe I93 and thevalve I2 is moved in one direction, the piston 59 will becorrespondingly moved by the advance of fluid pressure from the pipe EI, and at the same time the fluid pressure on the other side of thepiston will flow out of the cylinder through the pipe 59, to the exhaustthrough the pipe I14. The exhaust from the pilot system will flow fromthe valve casing I2, pipe I94, through the valve ISI, pip I92, to theexhaust pipe I82.

The action of the injection plunger is also controlled by the valve I95which is also preferably a manually operated valve, the casing of: whichhas communcation by means of the pipe I95 with the pilot pipe I18 andhas communication by means of a pipe I9I with the exhaust pipe I82.Leading from the valve casing I95 is a pipe I98 which has communicationwith the casing of the valve I I7 and a pipe I99 also has communicationwith the valve Ill and the valve casing I95, so that when the valve I95is set to direct the fluid pressure beneath the piston 88 to raise theinjection plunger, the fluid pressure to operate the valve will be fromthe pilot pipe IIS, through the pipe I99, valve I95, pipe I98, to thevalve H1. The fluid pressure to the cylinder 5'! will then be throughthe pipe II5 beneath the piston 88. At the same time fluid on the otherside of the piston 88 will be exhausted from the cylinders 8I throughthe pipe H9, valve III to the exhaust pipe I5'I.

Thu it will be seen that by manipulating the various valves 1811-485 and191 as well as the valv 164, the operation of the various parts of thepress may be controlled.

The pip 155 also has communication with a discharge or outlet pipe 2E0and in the operation of the pump 152 to build up the necessary pressurein the system such pressure is controlled by means of the necessarypressure regulating valve 26| in the pipe 155 and this pressureregulating valve 28! will also operate as a relief valve.

When the part of the mechanism to which the pressure is applied (such asthe slide) reaches the limit of its movement or meets with sumcientresistance, then no more fluid in volume can be supplied to theoperating parts, but the pump 152 will still be operating, and byattempting to force more fluid into the system, the relief valve 201will open to handle the surplus fluid and the pump 152 will then operateto discharge the fluid at full pressure back to the tank or source ofsupply through the pipe 154, past the valve 115, through the valve 251and out through th pipe 200 back to the tank or source of supply.

However, such a condition will result in the loss of power and in orderto obviate such loss a supplemental relief valve 252 is provided in thepipe 154 and connected also to the casing of the valve 202 is an exhaustpipe 203.

This valve 252 is operated at a predetermined time in the operation ofthe mechanism and the means for controlling the operation of this valve292 operates to automatically open the valve, with the result that thefluid at low pressure will be discharged from the pump 152 through thepipe 154, past the valve 252 into the pipe 203 and back to the tank orsource of supply.

However, at this time and although the fluid is being discharged backinto the tank or source of supply by pump 152, it is necessary tomaintain the predetermined fluid pressure within the system and againstthe actuated parts, that is, such as against the slides, etc. This maybe accomplished by the use of the pump 1'16, which is preferably of asmaller capacity and connected with the system so as to supply thenecessary fluid to maintain such pressure, such connection being made bymeans of a pipe 204 which has communication with the pipe 118 and inwhich pipe 264 is arranged the necessary control valve 255. The outputof the pump 1'16 is prevented from discharging through the main pump1-52 by means of the check valve "5. This pump 1'16 directs fluidthrough the pilot system 118- and the direction of flow in this pilotsystem is controlled by the manually operated valves 186- 13U19| and 195so as to direct the fluid to one side or the other of the respective4-way valves 45, '13, 85 and Ill to cause a change in the direction offlow of the fluid to one side or the other of the respective operatingpistons.

The valve 255 will not open to permit fluid to be supplied to the systemby the pump 116 until the pressure from the pump I16 exceeds the prestheopening of the valve-20'! is accomplishedby venting the valve 25'!through'the pipe 209.

A vent line 211! normally maintains the valve 202 in a position that thepump 152 will cause fluid to flow therethrough into the system and isoperated so as to be positioned to cut out the supply of the fluid fromthe pump 152 with respect to the system and cause the fluid circulatedthereby to flow back to the supply through the pipe 203.

The valve 2532 is operated at a predetermined time in the operation ofthe system, automatically, and in any desired or suitable manner,preferably by means of a valve operating mechanism 211 (see Figures 8and 21) which in turn is controlled in its operation by'the fluidpressure in the system and which controls an electro responsive device212 (see Figure 21) controlled by a clock mechanism 213 which operates avalve 214 to permit fluid pressure to unbalance the valve 202, the valve214 controlling the fluid pressure in the pipe 215.

The timer 213 is initially set to operate at a predetermined time afterthe commencement of any sequence in the operation of the mechanism.

There may be times when it is desired to maintain the valve 202 open fora prolonged period and to that end there is provided a by-pass 216preferably manually controlled by a valve 211, by-passing the fluidaround the valve 214 and the by-pass 216 and the valve 2 1'! may be anordinary valve toopen and close the by-pass.

A manually operated pressure regulator 218 is provided for remotecontrol of the pressure through the valve 201, one side of the latterbeing connected with the valve 218 by a pipe 2'|8-a and the other sideof the valve 218 is connected with an exhaust pipe 2l8b so that byoperating the valve 218 the pressure in the system which it is necessaryto maintain may be increased or decreased. That is, the pressurenecessary to operate the valve 201 may be varied at will.

Another (pump 219 operates as an auxiliary source of pressure fluid tosupplement the supply from the main pump 1 52, and to normally by-passfluid from the supply pipe 220 back to the supply through the pipe 221and this circulation is controlled by a valve 222 being opened, and theopening of this valve is accomplished by unbalancing the fluid pressurewhich operates it by reason of a valve 223 being opened and which valveis controlled'by the operation of the piston 88 and the piston rod 91.The element 1M carried by the piston rod -91 when th piston 88 islowered operating to open the valv 223. This valve controls the ventingline 224 which communicates with the casing of the valve 222 and theexhaust pipe 132.

This valve 223 may be of any desired construction but is preferably anordinary open and shut valve. When this valve 222 is opened, pressure isexhausted through the pipe 221. When the injection plunger 93 and thepiston 88 move upwardly to permit the valve 223 to close, the valve 222will be positioned so that an extra volume of fluid will be supplied tothe cylinder 8'3 through the line 155 for rapid injection of thematerial from the injection cylinder and into the mold.

A check valve 225 is provided in the pipe 54 between the pump .219 andthe line 155, and a check valve 226 may also be provided in the pipe151. Pressure gauges 22'! may also be provided in the line 151 on bothsides of the valve 226 so as to indicate different pressures, while

